JP2007143490A - A method for diagnosing vegetation by aerial balloon multiband sensing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously diagnose the amount of vegetation biomass and the degree of stress in vegetation diagnosis by image analysis, and to evaluate qualitative traits such as moisture stress and pest damage stress as well as quantitative characteristics of vegetation.
SOLUTION: A visible light camera, a near-infrared camera, and a thermal infrared camera are mounted on a balloon that can be controlled by remote control, and a vegetation in a range to be diagnosed from the air by flying the balloon is visible light camera, near-red An NDVI image is obtained from an R image obtained by an outside camera and a thermal infrared camera, obtained from a visible light camera and an image obtained by a near infrared camera, and the thermal obtained by the NDVI image and the thermal infrared camera. Vegetation is diagnosed by infrared image.
[Selection] Figure 2

Description

  The present invention relates to a method for vegetation diagnosis by balloon aerial imaging multiband sensing.

  Shooting from artificial satellites and aircraft as methods for investigating the growth of plants on the surface, investigating landslides, landslides and debris flows in forests and hills caused by heavy and long rains, and monitoring widespread forests and hills Development of sensing technology is underway. Remote sensing by satellite is a country with a lot of rainfall like Japan, and the target area cannot be observed sufficiently during heavy rain and long rain, and the number of observations is limited. There is a problem that you can't.

  By using an aircraft, it is possible to obtain an image and a photograph of the target area at a time when it is necessary, but there is a problem that the necessary cost increases. As aerial photography methods, methods using radio control aircraft, Cessna aircraft, and helicopters have been developed, but there are problems in terms of cost, safety, and the like. For aerial photography, balloons are considered advantageous from the standpoints of cost and safety.

For example, the following literature discloses the evaluation and diagnosis of the surface condition and vegetation condition.
JP 2004-151092 A JP 2004-147651 A Haruhiko Yamamoto and two others "Detection of the location of rice blast disease using thermal infrared images" (Japan Crop Science Society, 64, 467-474, 1995) Haruhiko Yamamoto and two others "A remote measurement evaluation of the burning state of trees by thermal infrared imaging and application to pyroclastic flow damage at Unzen Fugendake" (Symposium on the use of remote sensing data in the field of geotechnical engineering, 213-220, 1993) Patent Document 1 describes a vegetation health monitoring method for detecting abnormal parts such as cracks in natural slopes. This is based on infrared thermal imaging of vegetation to quantitatively grasp the surface temperature behavior of vegetation. On the other hand, the temperature rise location is depicted, while the spectral reflection characteristics of the vegetation are detected, the vegetation activity is quantitatively grasped and the activity fall location is depicted, and these temperature rise locations and activity fall locations are visible digital images It is displayed on the top to identify the vegetation activity drop.

  In Patent Document 2, an infrared thermal image of the target vegetation is captured, the surface temperature behavior of the vegetation is quantitatively grasped, a temperature rising vegetation is depicted, and the possibility of a decrease in the activity is grasped. It describes the health monitoring method of vegetation by detecting the characteristics and confirming the vegetation activity, and when the activity is low, performing maintenance such as fertilizer application and replanting.

  In these Patent Documents 1 and 2, an increase in the surface temperature and a decrease in the activity of the vegetation are obtained from an infrared thermal image and spectral reflection characteristics, and RVI or NDVI is used as a vegetation index. NDVI is called a normalized vegetation index and is generally used as an index representing the degree of vegetation activity. Further, the R image of the visible image depends on the level of reflectance due to the amount of red selective absorption based on the amount of chlorophyll in the vegetation. From this, the product of the degree of vegetation overgrowth and the amount of chlorophyll is considered as the amount of biomass (amount of biological resources). However, the diagnosis of vegetation requires the evaluation of qualitative traits indicating the degree of water stress and pest stress in addition to the evaluation of quantitative traits such as biomass amount. Is not taken into account.

  In Non-Patent Document 1, diagnosis of decrease in transpiration due to rice blast disease is based on measurement and analysis of thermal infrared images. In Non-Patent Document 2, thermal infrared images are used to indicate the state of combustion of trees. Although it describes about using for remote measurement evaluation, it was not evaluated together with an NDVI image and a thermal infrared image, and it was not enough to perform an appropriate vegetation diagnosis.

  In the conventional diagnosis of vegetation by image analysis, the amount of vegetation biomass and the degree of stress are not diagnosed at the same time, and quantitative characteristics of vegetation are evaluated. The qualitative traits have not been evaluated, which is insufficient for vegetation diagnosis.

  The present invention has been made to solve the above-mentioned problems. A visible light camera, a near-infrared camera, and a thermal infrared camera are mounted on a balloon so as to be controllable in a remote control manner, and the balloon is allowed to fly. Photographing vegetation in a range to be diagnosed from the air with the visible light camera, near infrared camera, thermal infrared camera, R image obtained by the visible light camera and image obtained by the near infrared camera, Vegetation is diagnosed by acquiring an NDVI image from the NDVI image and the thermal infrared image obtained by the thermal infrared camera.

  According to the present invention, a visible R image obtained by a visible camera mounted on a balloon, an NDVI image obtained from a near infrared image obtained by a near infrared camera, and a thermal infrared image obtained by a thermal infrared CCD camera are obtained. Since the vegetation state is diagnosed by using this, a detailed vegetation state can be judged in a wide range, and the necessary expenses can be significantly reduced.

  In the present invention, a camera unit as shown in FIG. 1 is used for vegetation diagnosis. The camera unit 10 includes a visible light camera 1, a near-infrared camera 2, and a thermal infrared camera 3, each of which has a digital camera, and a control device 4 for photographing operation and transmission / reception of the cameras 1 to 3. . Each of the cameras 1 to 3 has a memory necessary for storing and holding the photographed image, and the control device 4 has a transmission / reception function, and receives a command signal of the photographing operation of each of the cameras 1 to 3 by remote operation. It is preferable to perform control so that monitor images of the cameras 1 to 3 can be transmitted.

  FIG. 2 shows a situation in which a camera unit 10 as shown in FIG. 1 mounted on a balloon 20 is photographed by the operation control device 30 on the ground. By adopting a lightweight and small camera 1 to 3 and the control device 4, a small balloon having a total length of about 6 to 7 m can be used.

  The operation control device 30 transmits an operation command signal so as to perform the photographing operation of each of the cameras 1 to 3 of the camera unit 10 and receives a signal transmitted from the camera unit 10 mounted on the balloon 20 and a monitor image signal. And a display device for monitoring the data. If the monitor images of the cameras 1 to 3 are transmitted from the camera unit 10, the shooting operation can be performed while viewing the monitor images.

  The ground surface is photographed while the balloon is moored at a height of, for example, about 200 m above the ground. If the cameras 1 to 3 in the camera unit 10 have a posture control function, the posture control of the cameras 1 to 3 is performed while viewing the monitor images of the cameras 1 to 3 by the monitor on the operation control device 30 side. Can be taken. If the cameras 1 to 3 are not equipped with posture control, the cameras 1 to 3 are set in advance in a state where an appropriate image can be taken at the assumed position from the ground surface, and shooting is performed at the assumed position. become.

  The lens of each camera 1 to 3 is a standard to wide-angle lens considering the height of about 200 m above the ground. As a simple lens, a fixed focus lens may be used, but the altitude of shooting changes to some extent. When taking this into consideration, it is preferable to use a lens having an automatic focusing function, and if it is necessary to change the angle of view, a wide-angle zoom lens is preferable. However, when considering mounting on a balloon, the function is appropriate from the weight of the camera unit 10.

  When photographing for vegetation diagnosis, the camera unit 10 is moored at a position where photographing is performed with a balloon equipped with the camera unit 10, and photographing is performed by operating each of the cameras 1-3. Each of the cameras 1 to 3 has a memory for a necessary captured image frame, and the captured image is stored and held.

  In this way, vegetation diagnosis is performed using the images taken by the cameras 1 to 3 mounted on the balloon. An NDVI image is acquired from the R image of the image of the visible light camera 1 and the image of the near-infrared camera 2, and the NDVI image and the thermal infrared image obtained by the thermal infrared camera 3 are combined to diagnose vegetation. I do. For vegetation diagnosis, an application for performing image analysis and a personal computer having necessary storage means are used.

  In the NDVI image, the amount of biomass is evaluated as a quantitative trait of vegetation, and the qualitative evaluation that expresses the degree of water stress and pest damage stress is performed by a thermal infrared image to accurately detect the state of vegetation and grow. By taking appropriate measures according to the amount and the degree of stress, it becomes possible to maintain and manage the vegetation in a healthy state.

It is a figure which shows roughly the structure of the camera unit used for the vegetation diagnosis by this invention. It is a figure which shows the condition which mounts a camera unit in a balloon and performs imaging | photography operation by the operation control apparatus on the ground surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Visible light camera 2 Near infrared camera 3 Thermal infrared camera 4 Control apparatus 10 Camera unit 20 Balloon 30 Operation control apparatus

Claims (1)

Mounting a visible light camera, near-infrared camera, and thermal infrared camera on the balloon so that it can be controlled remotely.
Shooting vegetation in a range to be diagnosed from the air by flying a balloon with the visible light camera, near infrared camera, thermal infrared camera,
Obtaining an NDVI image from an R image obtained by the visible light camera and an image obtained by a near-infrared camera;
Diagnosing vegetation from the NDVI image and the thermal infrared image obtained by the thermal infrared camera;
A method of diagnosing vegetation by balloon aerial multiband sensing, comprising:

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